ABSTRACT

Many techniques are used to lay pipe, each technique having specific advantages when operating under special conditions. The Reel Pipelaying Technique has the advantage of low operating cost and is especially suitable for pipe with diameters of 12 inches or less. With the Fluor RB-2 reel barge, miles of pipe are welded together on shore and spooled onto the reel. Then, the barge moves to the right-of way and lays continuous lengths of pipe at the rate of 1 to 2 miles per hour.

In evaluating the effectiveness of a reel barge, several obvious technical problems should be considered. The possibility of a failure due to low cycle fatigue was evaluated. This study indicated that this type of failure should not occur. The ductility of the welds was evaluated and found to be adequate. Oval-ling of the pipe is limited to ± 1% by proper selection of pipe diameter and wall thickness. The radius of the reel was selected as 20 feet based upon extensive analytical studies.

The pipe handling equipment includes many special design features which allow the pipe to be laid rapidly and efficiently. Much of this equipment is automated so that careful control is maintained over pipe bending, straightening and laying functions. The equipment includes a large reel, an aligner pipe straightening devices, a tensioner, stanchions, and stern thrusters.

Actual design of Fluor RB-2 commenced in December, 1968. The basic hull was launched in December, 1969, with the outfitting finished in the Spring of 1970. Thus in only 16 months this highly complex Reel Pipe Laying Barge was developed, designed and constructed.

The economical and technical feasibility of laying large diameter pipe (6 inches through 12 inches) has been demonstrated through the use of Fluor's patented Reel Pipelaying Technique aboard the RB-2.

INTRODUCTION

It has been stated frequently that "Necessity is the Mother of Invention". This has certainly proven correct with respect to the Reel Pipelaying Technique.* Critical construction schedules dictated its development for use following the Normandy Landing during World War II. A need for high speed, economical installation of small pipelines precipitated the development of the U-303 by Aquatic Contractors and Engineers, Inc. which is now an operating division of Fluor Ocean Services. Since the U-303 became operational in the early 1960's, seven million feet of pipe, ranging in diameter from 2 inches to 6 inches, have been laid in water depths up to 350 feet. This decade will focus even greater attention on the significant need for a further technological breakthrough for laying larger diameter pipe offshore. To attain the phenomenal rate of growth which is predicted for the offshore industry in the next ten to twenty years, it is evident that:

  • We will operate in locations where extremely adverse weather conditions are prevalent, such as the North Sea and the Bass Straits.

  • The high production rates required to make deep water reservoirs profitable, will necessitate the utilization of large diameter pipelines in water depths which far exceed present industry capabilities.

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